1. Field of the Invention
The present invention relates to, for example, an insulating film, a transistor, and a semiconductor device. The present invention relates to, for example, methods for evaluating an insulating film, a transistor, and a semiconductor device. The present invention relates to, for example, methods for manufacturing an insulating film, a transistor, and a semiconductor device. The present invention relates to, for example, an insulating film, a display device, a light-emitting device, a lighting device, a power storage device, a memory device, a processor, and an electronic device. The present invention relates to methods for manufacturing an insulating film, a display device, a liquid crystal display device, a light-emitting device, a memory device, and an electronic device. The present invention relates to a driving method of a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a memory device, and an electronic device.
Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. In addition, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter.
In this specification and the like, a semiconductor device generally means a device that can function by utilizing semiconductor characteristics. A display device, a light-emitting device, a lighting device, an electro-optical device, a semiconductor circuit, and an electronic device include a semiconductor device in some cases.
2. Description of the Related Art
A technique for forming a transistor by using a semiconductor film over a substrate having an insulating surface has attracted attention. The transistor is applied to a wide range of semiconductor devices such as an integrated circuit and a display device. Silicon is known as a semiconductor applicable to a transistor.
As silicon which is used as a semiconductor film of a transistor, either amorphous silicon or polycrystalline silicon is used in accordance with the purpose. For example, in the case of a transistor included in a large display device, it is preferable to use amorphous silicon, which can be used to form a film on a large substrate with the established technique. In the case of a transistor included in a high-performance display device where driver circuits are formed over the same substrate, it is preferred to use polycrystalline silicon, which can form a transistor having high field-effect mobility. As a method for forming polycrystalline silicon, high-temperature heat treatment or laser light treatment which is performed on amorphous silicon has been known.
In addition, a transistor using an oxide semiconductor film is disclosed (see Patent Document 1). An oxide semiconductor film can be formed by a sputtering method or the like, and thus can be used for a semiconductor film of a transistor in a large display device. Moreover, a transistor including an oxide semiconductor film has a high field-effect mobility; therefore, a high-performance display device where driver circuits are formed over the same substrate can be obtained. In addition, there is an advantage that capital investment can be reduced because part of production equipment for a transistor including amorphous silicon can be retrofitted and utilized.
As a method for examining characteristics of an oxide semiconductor film performed under a condition without contact with the oxide semiconductor film (contactless method), a method in which the oxide semiconductor film is irradiated with excitation light and a microwave and a reflected wave of the microwave changing by irradiation of the excitation light is measured is disclosed (see Patent Document 2 and Patent Document 3). Patent Document 2 shows that in the case of an amorphous oxide semiconductor film, the penetration length (also called penetration depth) of excitation light with a wavelength of 349 nm is approximately 10 nm.
Non-Patent Document 1 discloses a relation between conductivity and spin densities measured by electron spin resonance (ESR) of an In—Ga—Zn oxide that is a typical oxide semiconductor. As a carrier source of the In—Ga—Zn oxide, defect states caused by oxygen vacancies and hydrogen are given.